Which of these pests is known to leave residues on ornamental plants due to their feeding habits?

Aphids are small sap-sucking insects that are well-known for their feeding habits, which involve piercing plant tissues and extracting sap. As they feed, aphids excrete a sticky substance known as honeydew. This honeydew can accumulate on the surfaces of ornamental plants, creating a shiny residue. The presence of honeydew not only affects the appearance of the plants but can also lead to the growth of sooty mold, which can inhibit photosynthesis and further impact the health of the plants.

In contrast, chinchbugs primarily feed on grasses and do not produce honeydew; they cause damage by sucking out the plant sap, but their feeding does not typically leave a noticeable sticky residue on the plants. Bluegrass billbugs also focus on grasses, with their feeding resulting in different types of damage, such as cutting or living within plant tissues rather than leaving residues. Pokeweed is a plant rather than a pest, so it does not have feeding habits that produce residues on other plants.